Liquid vs. Bar in Dr. Bronner’s Pure Castile Soap


The liquid came first – peppermint to be exact. Bar soap meandered in a few decades later. While there are hardliners in both camps, the difference between liquid and bar is mostly a matter of personal preference. However, there are some differences between the two.

Here are the ingredients side by side for the unscented Baby Mild castile soap. I chose our simplest soap, which lacks any essential oils, so that the differences are easier to see.

Comparison of Liquid vs. Bar Castile Soaps

Differences explained:

  • Liquid contains more water.
    • Why: There is just enough water in the liquid soaps to keep them liquid. Any less water and the soap begins to solidify. To test this, leave the cap off your bottle for a day, and you’ll notice the soap’s starting to gel. You can reliquify it with a bit of water. (The thickness, or thinness, of the soap is not due to high water content, but to the consistency of the various oils.)
    • Effect on Performance: None
  • Liquid uses potassium hydroxide to saponify oils; bar uses sodium hydroxide.
    • Why: Hardness – sodium hydroxide produces a harder soap than potassium hydroxide. The purpose of these strong alkalis is to blast apart the oil molecules, separating the glycerin from the fatty acids. The fatty acids then reattach to the sodium or potassium ion, leaving the glycerin and water (hydroxide) free-floating. (Just a sidenote – soap cannot be made any other way. None of these alkalis are left in the soap. Check out the link at the bottom about soapmaking.)
    • Effect on Performance: None
  • Bar contains palm oil, in addition to coconut oil.
    • Why: Palm oil hardens more than coconut oil. Coconut oil, even in its solid state, is mushy, and it melts at 76° F.
    • Effect on Performance: Bar soap is slightly more moisturizing. Palm oil contains stearic acid, which some people find to be less drying than the lauric acid found in coconut oils.
  • Bar contains salt (NaCl – sodium chloride or table salt).
    • Why: Also serves as a hardener.
    • Effect on Performance: Bar soap is slightly more moisturizing. Since our bodies are slightly salty, salt water is gentler on our skin than pure water. Salty soap is, too.

Other Differences in Formulation:

  • How the Hemp and Jojoba oils are added:
    • In the liquid soaps, the hemp and jojoba oils are saponified, i.e. turned into soap, along with the coconut and olive oils. However, in the bar soaps, these two oils are added unaltered after the saponification process. This is called “superfatting” the soaps. A while back my brothers tried superfatting the liquids with the hemp and jojoba oils, but found that the oils separated out and floated to the top.
    • Effect on Performance: Bar soaps produce a creamier lather and are slightly more moisturizing.
  • Amount of Essential oils:
    • This is only relevant to the scented soaps (everything except the unscented Baby Mild). The liquid soaps have a higher percentage of the essential oils than do the bar soaps. Once again, the issue at stake is hardness. The bar soaps would soften with that high a concentration of the essential oils.
    • Effect on Performance: This is entirely a matter of personal preference. Those who like an intense whiff of scent, and those who are looking for the specific benefits of the particular essential oils, should opt for the liquids. Those who like a little scent, but not too much, the bar soap would be better.

Differences in usage:
For all body applications, they are entirely interchangeable – from washing face, hair, or body, or shaving. For around the house purposes, you would need to take the extra step of dissolving the bar soaps in water before using them in a spray bottle solution, but they are equally effective. Also, the bar soap can be grated to achieve a kind of powdered soap for laundry, although the liquid works just as well.

Volume of actual soap:
I don’t know how to de-math this, but people who put together their own recipes for cleaners might want to know this. Bar soaps are 5% water; liquids are 61%. The chemistry is a little different for both, but considering that a bar of soap weighs 5 oz, and thus 4.75 oz of it is soap, you would need 12.18 ounces (a little over 1 ½ c.) of liquid soap to equal the soap content of a 5 oz bar. Doing the math the other way, 1 cup of liquid soap equals approximately 2/3 of a bar (or 3.64 oz.) of Dr. B’s bar soap.

Bottom Line:
The Dr. Bronner’s Bar and Liquid Pure Castile soaps are interchangeable. However, the bars are slightly more moisturizing. The liquids are slightly more scented.

If you want more info on the process of soapmaking, check out this article:

If you have any other questions about what is in the soap and why or where it is sourced and why or anything else, let me know!


165 thoughts on “Liquid vs. Bar in Dr. Bronner’s Pure Castile Soap

  1. Can you recommend a type of dispenser for Castile oil when used in shower? As you discussed in the past it does clog and spews liquid out on its own. Someone mentioned dish detergent dispenser. Thank you

  2. Hi Zen – There is no sodium hydroxide in the Dr. Bronner’s soap that you’re buying. The NaOH molecule is completely split apart and it’s parts reattach to other molecules, forming completely different substances: soap (scientifically called sodium cocoate) and water. You can read more about the chemistry behind it here: Let me know if I can be of further help!

    Hi Larry – Most of our soaps are either induction sealed or pressure sealed. Only the 2 oz and 4 oz bottles are not.

    Hi Erin – The only dispenser that works is a foaming pump dispenser. Dilute the soap at a 1:5 ratio with water for that. I do not recommend the dish detergent dispenser.

    All the best,

  3. Lisa, Thank you for your work on this blog. I’ve used Dr. Bronner’s for years and enjoy the soaps a lot. But they are a little more expensive than other options, and lately I’ve become a more frugal about such things, so I’ve been trying to figure out the most cost-efficient way of using it. (I just use it in the shower, not around the house.) I noticed with interest your comment that the soap content in a 5 oz. bar equals the soap content in 12.18 oz. of the liquid soap. But it seemed like your calculation was assuming an equivalence between the bar’s “ounces” (measuring weight) and the liquid’s “ounces” (measuring volume). But those two kinds of “ounces” aren’t usually equivalent, are they? I trust you know what you’re talking about, but would mind explaining why the volume/weight distinction isn’t affecting your calculation?

  4. Hi Kirk – I absolutely love having occasion to draw on those high school chemistry classes now that I am an adult! (I am totally serious. I’m a bit of a nerd.) So! As you astutely pointed out, in our totally convoluted system of weights and measures in America, we use the same word “ounce” for a liquid measurement (equaling 2 Tablespoons) and a dry measurement (equaling 1/16 of a pound). The correlation between the two is that at sea level, one liquid ounce of water also equals 1/16 of a pound. However, anything with a density different from water will have a different liquid measurement from dry. Stick with me here – I’m getting somewhere. Now, I do not know the exact density of Dr. Bronner’s castile soap. It is a blend of ingredients, but is mostly made up of oils. I’ll go with the density of olive and coconut oils because those are the main ingredients. Both of these oils are slightly less dense than water, but at the amounts we’re referring to in these recipe conversions, they would easily round up to 1 liquid ounce oil = 1 weight ounce oil.

    That means, that for most household purposes, in comparing the soap quantity in Dr. Bronner’s bar to the soap quantity in Dr. Bronner’s liquid, you can pay little attention to liquid vs. dry ounces.

    If you are planning some sort of large scale project, where the slight difference between the liquid vs. dry would be multiplied, please let me know and I will be happy to do a more exact calculation for you.

    Thanks for asking!

    All the best,

  5. Thank you so much for your prompt reply and explanation. Good to know our system of measurements isn’t completely arbitrary!

    Anyhow, based on your conversion formula, an ounce of undiluted soap costs about 30% more if bought as a liquid instead of in a bar (or more, if you buy the liquid in smaller bottles). That would predispose me to buying the bar soap… except that my anecdotal experience is that I go through the bars much more quickly than the liquid. That seems counter-intuitive since the bars have a higher concentration of soap. Is that something you’ve encountered? Do you have any idea why the bars go faster? I wonder if it’s because I don’t use a wash cloth?

    • Here’s a good tip. Remove them from the packaging and let them dry out for a couple of weeks before you use them. They will last twice as long! The packaging keeps them slightly moist and makes them dissolve faster. I know it seems like a long time to wait, but if you plan ahead it will pay off.

  6. I just discovered your blog. Awesome explanations. Is it OK to use the bar soap as a face cleaner? I make my own coconut oil cleanser at night, but was looking for a bar soap for my morning showers to use on my face.
    Thank you.

  7. @Flo:
    I use the baby mild bar soap on my face, hair and body every day. At first I developed some small dry patches on my face but I used coconut oil as a moisurizer before showering and soon the dry patches went away. I believe it was my skin adjusting to the new soap. I also make my own sugar scrub with coconut oil, cocoa butter and turbinado sugar and I use that to exfoliate my face once a week, before showering, and then I wash my face with the bar soap. The result is very soft but not greasy skin.

  8. I’ve been using the Tea Tree scent for my hair and my acne-prone skin and it’s been working great! It’s so awesome to find a pure product that I can use to wash my hair, face, body, and veggies, too. The soap’s brought out my hair’s natural wave, which is great as it could sometimes be hidden by the chemicals in traditional shampoo. I didn’t use any rinses after the soap and it didn’t leave a greasy residue like I read could happen. Should I continue to use just the soap or would it be beneficial to use some sort of rinse afterwards?
    Love the blog and the product! Keep up the good work!

  9. I don’t really have a recipe but I think the last time I made a batch I used about 50-50 coconut oil and cocoa butter (melted in the microwave) and then I mix in the turbinado sugar until its the desired consistency. I have also added almond oil if the mixture is too thick; if the mixture is too hard at room temperature, melt it in the microwave and add more coconut or almond oil. I like sugar better than salt since salt can sting if you just shaved but I have made it with both. Salt works as a water softener and it leaves skin very soft so it can be used in place of the sugar if desired. Turbinado sugar can be too course for some people so you might also try regular white table sugar. You can use any combination of oils that you like and even add a drop or two of essential oils. I have made a salt scrub with lavender oil which is good to use before bedtime. Try making small batches till you find what you like. Be careful not to get any water into it or else the sugar and salt will dissolve.

  10. Thank you, Diane. I wonder how would be if I used coconut sugar. May have to try.

  11. LISA,

    I’ve read all the above and no one has really mentioned a much more serious matter (for those who have it) but my acne prone skin on my face.. struggled since i was 18 and I’m 23 now and it really stinks to see people eat crap day and night and never clean them selves or there bed sheets and there face is perfectly fine. but I’m over here like what the hell is life.. lol… :( ANYWAYS what is the best to use for my face?? I’ve used every stupid lying product on the market and did all the prescription stuff and all that is a lie and the government just wants my money and they get the doctors to lie. i tried the tea tree bar soap for a bit and it sort of worked a bit i guess but i think maybe my schedule of face washing might be the problem. a year ago i started washing my face and body at night with warm hot water then just rinsing off in cold water in the morning. seeing as washing my face with chemicals in the morning causes much more irritation in the skin since the sun is out. but i recently switch to the liquid version tea tree and its kind of made it worse. but it could just be getting used to it i suppose but once again i know there has to be a better schedule to use this stuff on my face like with certain water temperatures or times of the day and following up on it etc. i know these are questions for a “dermatologist” but that is bull crap I’m sorry I’ve been to a few and they all say different things so to me there all full of crap. :( wish big brother scientist governments would just release to the people the real cure for acne cause they obviously have it. but anyway sorry for kind of ranting i would appreciate your reply.. thank you much and i greatly appreciate it.

    • Zack, different Lisa here, something to check into for any type rash is a gluten sensitivity. But, a person will experience a detox rash as the gluten leaves your body. Keep in mind that you cannot just eat less gluten, the whole system is thrown off with even a tiny bit of gluten. The other thing is sugar. I will have facial eruptions with anything other than natural sugar, even coconut sugar, or too much juice, because of the concentration factor. I can use maple syrup. Not fun, but you will be healthier! Lisa t

    • You could look into Shea butter- it totally transformed my skin

    • I had severe “pizza face” adult acne until age 36. What worked for me was a morning routine of honey, olive oil and Dr Bronner’s unscented soap. In the morning I wet my hands with water, and massage in honey and leave on my face for 5-10 minutes. I then rise with a small amount of Dr Bronner’s liquid unscented soap. While the skin is still wet, I massage in extra virgin olive oil and let air dry. In 2 days my skin looked human again and has remained so in the past 7 years. Everyone I have shared this tip with, including hormone prone teens, and other adults like me that have struggled with skin problems have LOVED it. In terms of summer skin care, I use raw ivory shea butter; shea butter is a very mild natural sunscreen. Coconut oil is also a natural skin moisturizer that can also double as a deodorant to help improve the health of all your skin. The best thing about this treatment is that honey will moisturize your skin and shrink your pores. Dark spots will also be lightened more than you could ever believe. I am a black woman with keloid-prone skin and it worked for me so amazingly I still cannot fathom how different I look. People who did not know me prior to 2007 remark about my clear glowing smooth skin and cannot believe I ever had pizza face for 2/3 of my life. I have more comprehensive tips in a free booklet I share on that includes engineering controls for your home that includes liberal use of Dr Bronner’s products. Tea tree oil can be irritating to some individuals so I stick with the unscented Dr Bronner’s. I understand your pain but it can get better.

  12. It’s too bad that neither is Castille soap as: “Castile Soap or as it’s originally named in Spain Jabón de Castilla, is made exclusively with unrefined Extra Virgin Olive Oil. Unfortunately, pseudo called Castile Soaps that contain little or non Olive Oil in their formulations are widely available in today’s market. If it’s not made with 100% Olive Oil is NOT TRUE Castile Soap.”

    I see your bars in Trader Joes, shake my head and laugh as I walk away. Please stop calling this Castille Soap. Your ingredients are great but know what you are labeling first please.

  13. Lisa,

    I love your various blog topics. They are so informative.

    I am starting to recycle laundry water – I just set up a passive system and recycled my first load to water my plants. Perhaps later I will also reuse shower water. I want to reduce the amount of salt and other chemicals that I add to the soil. I am researching the best cleaners to use on laundry, house, and personal cleaning. How much salt is in Sal Suds and Castile bar soap?

    With grey water re-use in mind, how should I use Sal Suds or Liquid Castile for laundry? Borax is a no no for plant re-use so I won’t be using that. I suppose I also have to think about the pH of the grey water, don’t you think? It all seems to get so complicated when the water doesn’t disappear down a hole.

    And what about your hair rinse? Chemical composition. Grey water re-use friendly?

    Thanks so much.

    • I too would like to read a response about the soap being involved in grey water systems.

  14. I amused to using a moisturizer after washing my face but now that I am switching to this all natural remedy, I don’t want to use my formal moisturizer. I have acne prone skin, any suggestions?

  15. Hi, I am interested in knowing how can we turn the bar soap into liquid soap. It is insanely expensive to buy Dr Bronner here in Singapore. 2 FL OZ actually cost S$4.90!

  16. I have a question! I prefer the bar soap, however all of the different recipes I have call for a certain amount of liquid. I can’t use the liquid in these recipes, because it makes me itch (even the baby mild!)….. I am hoping that you can help me figure out how to dilute the bar soap with water (or however it should be done) so that I can use it in place of the liquid called for in all of the recipes….. Thank you so much!

  17. I have a recipe for laundry soap and it calls for a bar of fels-naptha dissolved into 4 cups of water. How would I substiute liquid dr. Bronners soap into this recipe? Thank you for any help.

  18. Good morning. I am stuck with about ten loads of laundry to do, and the only soap I have is for the body, though I have Tea Tree, baby, and almond . I thought I still had Sal Suds but apparently not. Can I use any of these in the washer? Thx.

  19. hi.
    so I have been on no-poo for 60 days.
    I have washed with egg, green tea, coffee, yoghurt. nothing works amazingly. still trying here!
    so my no-poo is basically, I can use anything on my hair which is natural.
    The hydroxide. is the only worry to me, but there is none left by the time the product is made? is this the ‘lye’?
    would you say I am safe to use your soaps as shampoo without breaking my 60 days!

    • Have you tried washing your hair with baking soda? and rinse with apple cider vinegar (1 Tbsp/cup water).
      It’s the only no-poo thing that worked for me. Shampoo are giving me terrible allergies of the skin. Any where my hair touches my skin … rash! (I’m guessing product residue). No poo– no rash…so far.
      I tried the Dr. Bronners Bar soap on my hair and it worked alright…the liquid didn’t work. I guess that’s due to the formula difference. Good Luck

    • My scalp used to itch ALL the time. I tried a million things including no-poo but nothing helped until I switched to JR Liggets bar shampoo (the one for dry hair). My hair has NEVER been better and my scalp has stopped itching for the first time in over 25 years. Plus, no plastic! I tried Dr. Bronner’s on my hair once, but I find their products too drying so I use them for household purposes only.

  20. Hi,
    I really like your soaps, but I am increasingly concerned with plastic pollution and want to avoid plastic packaging at all costs. Would you know the best way of converting your soap bars to liquid? It would be great if, sometime in the future, you could think of some system to reduce plastic waste (refills perhaps?). Thanks!

  21. I want to use the same laundry soap recipe I already have, but I don’t know how much liquid castile soap to use instead of the bar soap..CURRENT RECIPE 1/2 c. washing soda, 1/2 c. borax, 1/3 bar Fels Naptha bar soap,1 gallon +16 c. water. Can you please advise?

  22. What’s the reason of forming more foam with liquid soap more than with the bar soap?

  23. I noticed several diy body wash recipes using Dr. B. liquid castile soap. I was thinking of just trying to add a Bath and Body Works oil in a scent that I like to the soap. How would I dilute the soap and would I need to add anything else to use as a shower gel? I have never used liquid castile soap or tried making my own shower gel, but I would like to give it a try! Thanks

  24. I recently found your website and love it! Been using Dr Bronner’s off and on mostly on, since late 1960’s! I am so grateful for your comparisons of liquid to bar soap as I have been making laundry soap with liquid soap and most the recipes are for bar. Also, I really appreciate the information about soap vs detergent. I switched to SalSuds for cleaning. The hardest part for me is to use LITTLE enough!
    Are you still answering comments? I haven’t seen any answers dated since April 28, 2014.
    Best wishes, Deb

  25. I have switched to using just solid soaps to avoid plastic. Disposable plastic is creating a HUGE problem for our oceans and the environment in general (second only to climate change). Palm oil is also an issue because of deforestation and the large amounts of methane released when the forest is cleared for the palm oil plantations. I wish and hope that Dr. Bronner’s will take this issues into account sometime soon. It would be lovely to see their liquid soaps in a different kind of package.

  26. Hello, I would like to ask some questions that I have concerns about glycerin, sodium hydroxide, potassium hydroxide, that contains in castile soaps, are they safe for cats if I use in the house for cleaning, washing purposes ?. can my cat lick on it ? . Please let me know. Thank you. Minhtrinh

  27. @mina
    these ingredients are not “poisonous” but soap, in general, can cause gastric upset and diarrhea if consumed. I don’t use the liquid soap for floors and counters because it needs to be rinsed more than Sal Suds. I have two cats and two dogs and I use diluted Sal Suds for most cleaning tasks such as mopping floors (the floor in my house is 100% tile), counter top cleaning and I use it in my Rubbermaid spray mop for spot cleaning pet accidents on the floor. I don’t leave it in puddles on the floor but I also don’t worry about it being 100% dry and my cats walk over the damp floor on occasion and I have not seen any issues and I have been doing this since they were 2 lb kittens. IMO, these products are much safer for pets than commercial cleaners.

  28. Love all your products.
    Can you please advise if Dr Bronner’s liquid pure Castile soap be used in my HE washer?
    Many thanks

  29. Hi Lisa!
    I love this Dr.Bronners, and the forms of it, esp. the peppermint one. But i have a question. I bought yesterday a liquid from of peppermint liquid soap, 473ml. However today when i washed my body with it, it came a bit of water into the bottle, so i just wonder will it still have the same affect afterwards??

  30. This is for Tiffany who asked how to make liquid soap from dr. Bronners bar soap. Put it in a large ziplock bag with a cup r two of water – I use distilled – then close the bag tight and let it sit. It should take about five days to become soft and squishy but that depends on how warm it is. Mine took about 8 days because t has been cool here. Every day I would squeeze it around to help it along and had to add more water after a couple of days. When it is all “melted you just add water until it is the consistency you want for what you are doing. Mine is thick like partially set jello and I will use it in place of the fels naptha soap -which I cannot buy where I live- when I make laundry soap. To make hand soap I dilute it to a thin liquid and add a bit of oil ( your choice) then put it in a foam dispenser. If the bar you use is unscented you can also add several drops of essential oil to your liking. I hope this helps you Tiffany.

  31. Hi, i add some eo to castile soap and it has separation. I wonder which procedure cause the separation. Is the type of eo, or the type of bottle (i used pp bottle to store the castile) , or becauce it’s already cured? Some says that we need to put eo before curing time. Is it true? Thanks so much.

    • I added a teaspoon of liquid coconut oil to a foam soap dispenser and not only did it separate but it clogged my dispenser. I need to run clean, hot water through it to get the oil out so i don’t recommend adding oil to a foaming dispenser; it might working a regular soap dispenser but I haven’t tried it.

  32. Is Dr. Bronner’s liquid castille soap unrefined? Organic is not enough. IMO refined cancels out at least some of the organicness of an oil. See Paul Pitchford’s Healing With Whole Foods.

  33. Not a comment but a question, does this soap work with saltwater? I’m looking for a soap that I can use while salt water boating for personal hygiene.


  34. Where do I find Chloride-free, ph- neutral liquid soap for a dispenser?

  35. Which bar is better tea tree bar or tea tree liquid an should I add water to the liquid one because the oils are way stronger

    • If you’re needing the effects of tea tree oil, such as on acne or eczema, I recommend the tea tree liquid. Just use a couple drops for a face washing. Or mix some up in a foaming pump – 1 part soap to 3 parts water, or even more water. See what works best for you.

  36. I wear dentures. I brush gums, not teeth. I brush dentures separately. What do you perceive as the advantage to me (if any) of peppermint toothpaste over a drop or two of peppermint soap on a toothbrush? As far as I can tell, the taste seems pretty similar. And neither whitens my gums, of course 😉

  37. Wow, I was so excited when I finally found a product that I could use without worrying about added detergents and harsh chemicals but now I will no longer be using your product because even though it is natural and contains no harsh chemicals. It is destroying the planet. The use of Palm Oil in your product shows that you would rather choose profit over the Environment and countless number of species destroyed everyday because of the use of Palm Oil. It is extremely disappointing. I hope you reevaluate what kind of company you are and make better decision on the ingredients you put in your products. I will be spreading the word on what your product contains and the destruction is has on our planet and fellow species that share this planet with us.

    • Wow, Kristy. I didn’t know until I read your comment and then researched. Thanks for the enlightenment.

    • Hi Albo – I’d be interested to hear your thoughts when you’ve checked out the links I share with Kristy. I’m very glad you’re looking into this important issue.

      All the best,

    • Hi, Lisa. One place (among many) I looked was Dive Damai, which in turn yielded a link to the Union of Concerned Scientists. There, I found, “While purchasing certified sustainable palm oil is a good first step, it does not address all the negative environmental impacts associated with the production of palm oil.” However, with my usual due diligence I’ll keep reading. I care. Many sites (including UCS) allow for *both* sides of the story. And as an old fogey, I have plenty of time to read, decide, and pass on the garnered result.

    • Hi Kristy – I am so glad you brought this up. There has certainly been horrible devastation done to our planet and its species in the name of palm oil cultivation. This is unacceptable to us at Dr. Bronner’s and so we went on a search for a sustainable, Fair Trade, non-destructive source for palm oil. Ultimately, we founded a company called Serendipalm in Ghana. This operation is beautifully demonstrating how palm oil can be produced without the awful side effects seen in the Malaysian and Indonesian productions. Please check out our articles, and more importantly, our videos on our website under the Ethical Sourcing tab: And please do spread the word about this. There is a better way.

      All the best,

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